The present invention relates to a toothed belt.
Toothed belts made of polyurethane resin are used for purposes of high torque power transmission in machinery, such as machine tools, printing machines, textile machines, and injection machines.
Patent Document 1 (Japanese Patent Publication No. H5-62657), Patent Document 2 (Japanese Patent No. 2965403), Patent Document 3 (Japanese Unexamined Patent Publication No. 2006-112574) and Patent Document 4 (Japanese Unexamined Patent Publication No. 2010-96229) disclose a toothed belt comprised of an endless toothed belt body made of polyurethane resin.
In the endless toothed belt body of the Patent Documents 1-4, a cord is buried so as to form a helical pattern having a pitch in the belt width direction, and a nonwoven fabric is buried so as to be located at a position that is closer to the inner circumference of the belt than the position where the cord is buried.
Patent Document 5 (Japanese Patent No. 2954554) discloses a toothed belt comprised of an endless toothed belt body made of polyurethane resin whose inner circumferential surface where toothed portions are provided is covered with canvas.